1. Field of the Invention
The invention relates to a device for detecting leaks in a fluid-filled container. More particularly, the present invention relates to an apparatus and method for detecting leaks in an expandable device filled with fluid, such as a fluid-filled balloon, which is used to treat a patient's body tissue during medical procedures.
2. Description of Related Art
Fluid-filled balloons have been used in various medical procedures. For example, surgical balloons are sometimes used in endoscopic surgeries to create working space within a human body. Other medical balloons include thermal treatment balloons which are inflated within a body cavity, such as a cavity defined by a human organ, and filled with a heated fluid to impart thermal energy to the organ.
Application of thermal energy with fluid-filled balloons has been of particular use in treating tissue in body cavities of animals, including humans. For example, balloons filled with heated fluid have been used to effect coagulation and/or cauterization of a uterine endometrium. The distensible bladder is inflated to a predetermined pressure with a fluid so that the distensible bladder is in contact with substantially all of the tissue lining for which treatment is desired. The fluid is heated to a temperature sufficient to coagulate and/or ablate the tissue lining. The temperature and pressure of the fluid is controlled by means connected to the distensible bladder.
A concern in various medical procedures utilizing fluid-filled balloons is the potential for leaks in the balloon. The fluids used to inflate medical balloons may in some cases cause discomfort to the patient if allowed to leak from the balloon directly into the patient's body. Some fluids may even be toxic to the human body. Accordingly, it is often desirable to rapidly and accurately detect leaks in fluid-filled balloons.
Many leaks can be detected prior to use of a balloon through established methods, such as visual inspection of the balloon before the balloon is inserted into the patient. Detecting leaks prior to use of the balloon is not always possible, however, since leaks can form during a procedure, while the balloon is inside the patient and inflated with fluid.
Rapid detection of leaks can allow the surgeon or other user to rapidly deflate and remove a leaking balloon, thereby minimizing the amount of fluid leaking into the patient's body.
Various methods of detecting leaks during a procedure are known. The most common is visual inspection of the balloon. The balloon, however, can not always be easily viewed during various procedures, such as may be the case where the balloon is entirely within the patient's body (such as inside a human uterus). Some leaks, such as small pin-point leaks, cannot be easily seen even where the balloon itself is readily visible.
Another method of detecting leaks during a procedure involves monitoring the internal pressure of the balloon to detect drops in internal pressure, which are indicative of a leak. Some pressure drops, however, may not be of sufficient size to trigger a leak detection alarm, particularly for very slow leaks. Detecting pressure drops may be difficult in procedures during which fluid from inside the balloon is pumped out and continuously replaced with "fresh" fluid from outside the balloon. The constant inflow and outflow of fluid can create pressure variations that may make pressure-sensitive leak detection systems ineffective.
Consequently, there is a need to accurately and efficiently detect leaks in fluid-filled balloons used in medical procedures that allows for leaks to be rapidly detected during the actual procedure. The present invention satisfies these needs.